CN112543789B

CN112543789B - High-absorptivity resin and preparation method thereof

Info

Publication number: CN112543789B
Application number: CN201880096198.4A
Authority: CN
Inventors: 杨志亮; 杨昊; 杨阳; 马廷玉; 张香; 姚美芹; 姚金水
Original assignee: Shandong Haoyue New Materials Co ltd
Current assignee: Shandong Haoyue New Materials Co ltd
Priority date: 2018-06-22
Filing date: 2018-06-22
Publication date: 2022-12-27
Anticipated expiration: 2038-06-22
Also published as: JP2021528543A; US20210268139A1; EP3812422A1; JP7128302B2; CN112543789A; WO2019241986A1; EP3812422A4

Abstract

A sodium polyacrylate super absorbent resin for blood sucking with gradual hierarchical structure and its preparation method are provided. The high-absorptivity resin is a surface-modified sodium polyacrylate resin, and the surface modification comprises surface cross-linking by using a solution B prepared from a polyvalent metal salt solution A and a compound containing an epoxy group and a solvent.

Description

High-absorptivity resin and preparation method thereof

Technical Field

The present invention relates to a high-absorbency resin and a preparation method thereof. In particular to a high-absorptivity resin with a gradual hierarchical structure for blood suction, and more particularly, the invention relates to a sodium polyacrylate high-absorptivity resin and a preparation method thereof.

Background

High-absorbency resin, especially sodium polyacrylate high-absorbency resin, has been widely used in sanitary products such as sanitary napkins and diapers due to its excellent water absorbency and liquid absorbency, and also has wide applications in the fields of agriculture, industry, construction, medicine, light industry, chemical industry, and the like.

High-absorbency resins are generally required to have a high absorption capacity, an excellent absorption rate, liquid permeability, and a high gel strength when they are exposed to body fluids or the like. After the previous granular water-absorbing resin is contacted with an aqueous solution, the surface of the previous granular water-absorbing resin is easy to be bonded, so that granular polymers are bonded into blocks, so that fish eyes are easy to generate, namely, the so-called gel blocking effect is caused, further penetration of water molecules is hindered, the resin cannot fully exert the water absorption performance, and the water absorption rate, the water absorption speed and the like of the resin are influenced. Another disadvantage of the particulate water-absorbent resin is that it has a low gel strength and cannot meet the use requirements. Subsequently, in order to solve the above problems, various methods have been used to improve the properties of water absorbent resins, and surface crosslinking technology is one of them. The method improves the water absorption rate by carrying out surface chemical treatment on the water absorption resin, overcomes the defects of low gel strength and the like, and has higher application value.

For example, U.S. Pat. No. 4,188,950 discloses surface treatment with alcohols as dispersant and glyoxal as cross-linking agent, which can significantly improve the water absorption rate and gel strength of the resin, but the environmental problems of aldehydes are more prominent and are particularly difficult to apply to sanitary products. European patent EP91302895.7 discloses that a water-absorbent resin is placed in a high-speed stirrer, a treatment solution prepared from a polyol crosslinking agent is sprayed on the surface of the water-absorbent resin, and the water-absorbent resin is stirred and then placed in an oven for heating to perform a crosslinking reaction; this method greatly increases the water absorption rate, but requires expensive equipment. Japanese patent JP7242709 discloses dissolving a post-treatment liquid in a hydrophilic solvent, heating to change the post-treatment liquid into hot air, and allowing the hot air to pass through resin powder in a heated state to react with the surface of the resin powder; the method obviously improves the water absorption rate, but the treatment process is relatively complex and is difficult to operate. Further, the techniques disclosed in the above patent documents are all methods of surface crosslinking using a treatment liquid including a single crosslinking component, and the crosslinked layer formed is relatively single, and it is difficult to effectively solve the above-mentioned problems.

In addition, chinese patent CN 1696181A discloses that a sodium polyacrylate resin is treated by chemical crosslinking with a polyol or epoxy compound and coordination crosslinking with a polyvalent metal salt, which can achieve a good effect, but there is a compatibility problem between the two crosslinking modes, and as a result, the two crosslinking modes are merely physically superposed and do not have any necessary structural design, resulting in a less than ideal comprehensive performance, and performance indexes such as gel strength, water absorption rate, and water absorption rate cannot be improved at the same time.

Most importantly, these super absorbent resins generally have strong water absorption performance, and when these resins are used in the fields requiring blood absorption, such as sanitary napkins and surgical blood absorption, the absorption rate and absorption capacity cannot meet the requirements of blood absorption performance. This is because the resin can effectively absorb only the moisture in the blood, and when the moisture in the blood is absorbed, other substances are easily coagulated into lumps, which greatly hinders the experience in terms of comfort and the like, and the absorption rate, absorption amount and the like cannot meet the requirements in terms of blood absorption performance.

Disclosure of Invention

In order to solve the above-mentioned technical problems, the present inventors have developed a novel high-absorbency resin having excellent properties such as gel strength, etc. while achieving excellent blood absorption properties by surface-modifying the resin by combining organic crosslinking and inorganic crosslinking to have a graded hierarchical structure.

In a first aspect, the invention relates to a superabsorbent resin wherein the detection medium, when a blood simulant is used, is a resin according to ISO19699-1:2017 (E) measuring the blood absorption of the blood simulation solution to be more than or equal to 18.0g/g, preferably more than or equal to 18.5g/g; the blood-mimicking fluid absorption rate is 45s or less, preferably 40s or less, more preferably 38s or less.

When human blood is used as the detection medium, the detection medium is prepared according to ISO19699-1:2017 (E) a human blood absorption of 8.0g/g or more, preferably 8.3g/g or more, more preferably 8.6g/g or more; the human blood absorption rate is less than or equal to 45s, preferably less than or equal to 40s, more preferably less than or equal to 35s, and most preferably less than or equal to 25s.

In a preferred embodiment, the superabsorbent resin: based on the acrylic acid, the residual monomer amountLess than or equal to 1000mg/kg; the content of volatile matters is less than or equal to 10.0 percent; the pH value is 5.0-8.0; particle size distribution: the content of the sample with the grain diameter less than 150 mu m is less than or equal to 5wt percent, and the content of the sample with the grain diameter less than 106 mu m is less than or equal to 1wt percent; the bulk density was 0.65g/cm ³ -0.80g/cm ³ (ii) a And/or the whiteness is more than or equal to 70 percent.

In a preferred embodiment, the superabsorbent resin is a surface-modified sodium polyacrylate resin.

In a second aspect, the present invention relates to a method for preparing a superabsorbent resin, comprising the steps of:

(1) Weighing a surface dispersant;

(2) Weighing polyvalent metal salt, preferably aluminum salt, calcium salt, magnesium salt or zinc salt, more preferably aluminum salt, and preparing into solution A;

(3) Weighing a compound containing an epoxy group to prepare a solution B;

(4) Mixing the surface dispersant, the solution A and the solution B and the sodium polyacrylate resin;

(5) And carrying out crosslinking reaction to obtain the surface modified sodium polyacrylate super absorbent resin with a gradual hierarchical structure.

The sodium polyacrylate resin is an absorbable resin which is not subjected to surface modification and has an internal cross-linked structure, and the sodium polyacrylate super-absorbable resin is a super-absorbable resin which is subjected to surface modification (surface cross-linking) in the invention. The particle size of the sodium polyacrylate resin used in the present invention is preferably 120 μm to 830. Mu.m, more preferably 150 μm to 380. Mu.m.

In a preferred embodiment, the surface dispersant is selected from methanol, ethanol, acetone or fumed silica, preferably methanol or ethanol. The mass ratio of the surface dispersant to the sodium polyacrylate resin is (1-15) to 100, preferably (1-10) to 100, and more preferably (1-5) to 100.

In a preferred embodiment, the aluminium salt of solution a is selected from aluminium chloride, aluminium sulphate, aluminium ammonium sulphate, aluminium nitrate and alum, preferably aluminium sulphate or aluminium ammonium sulphate. The solvent of solution A is selected from water, acetone and polyhydric alcohol; preferably water and/or glycerol, and the mass ratio of the glycerol to the water is (0-0.7) to 1. The mass concentration of the aluminum salt in the solution A is 3-25%, preferably 8-25%, more preferably 10-20%. The mass ratio of the aluminum salt to the sodium polyacrylate resin is (0.010-0.050) to 1, preferably (0.025-0.030) to 1

The aluminum salt functions to form coordination crosslinks on the surface of the resin. If the dosage is too low, the crosslinked layer is too loose, and the crosslinking modification effect cannot be realized; if the amount is too high, the crosslinked layer is too compact and the pore size is reduced, thereby reducing the absorption amount and slowing the absorption rate.

In a preferred embodiment, the compound containing an epoxy group of solution B is selected from the group consisting of epoxy resins, epichlorohydrin, propylene oxide, glycidyl ethers, polyethylene glycol diglycidyl ether, and ethylene glycol diglycidyl ether; epichlorohydrin, glycidyl ether or polyethylene glycol diglycidyl ether are preferred. The solvent of solution B is selected from alcohols and ketones; preferably methanol, ethanol, isopropanol, acetone or butanone; more preferably ethanol or methanol. The mass concentration of the compound containing epoxy group in the solution B is 10-25%. The mass ratio of the compound containing an epoxy group to the sodium polyacrylate resin is (0.001-0.006): 1, preferably (0.002-0.004): 1, and more preferably 0.003:1.

The content of the compound containing epoxy groups in the solution B determines the content of the resin compact cross-linked layer and the size of the pore channel, if the content is too low, the cross-linked layer is loose, the gel strength cannot be ensured, if the dosage is too high, the cross-linked layer is too compact, and although the gel strength is increased, the absorption capacity and the absorption rate are seriously influenced.

The mass ratio of the aluminum salt in the solution A and the epoxy group-containing compound in the solution B to the sodium polyacrylate resin is equally important with the mass concentration of the aluminum salt in the solution A and the mass concentration of the epoxy group-containing compound in the solution B, and the aluminum salt and the epoxy group-containing compound in the solution B are all used for forming a gradual-change type hierarchical structure with proper cross-linking density on the surface of the sodium polyacrylate resin and ensuring that the resin has excellent comprehensive performance.

In a preferred embodiment, in step (4): uniformly mixing the surface dispersing agent, the solution A and the solution B, and then mixing with the sodium polyacrylate resin; or mixing the surface dispersant, the solution A and the solution B with the sodium polyacrylate resin in sequence; or mixing the surface dispersant, the solution B and the solution A with the sodium polyacrylate resin in sequence; or, the surface dispersant and the solution B are firstly mixed with the sodium polyacrylate resin uniformly, and then the solution A is mixed with the mixture obtained previously uniformly. Preferably, the surface dispersant and the solution B are firstly mixed and evenly mixed with the sodium polyacrylate resin at room temperature; subsequently, solution A is heated to 60-100 ℃, preferably 60-80 ℃ and mixed homogeneously at said temperature with the mixture obtained as described above.

In a preferred embodiment, the temperature of the crosslinking reaction in step (5) is 50 to 200 ℃, preferably 80 to 185 ℃, more preferably 120 to 140 ℃; the time is 20-210min, preferably 25-120min, more preferably 30-90min. When the materials are put into and taken out of the heating equipment by manual operation, the operation time is out of the time range; when heating in the continuous automatic production equipment, the connection time of the automatic material input and output heating equipment is not in the time range.

In a third aspect, the present invention relates to a superabsorbent article comprising the superabsorbent resin of the present invention.

In a preferred embodiment, the article may be, for example, a sanitary napkin, a medical blood-absorbing article, or the like.

In a fourth aspect, the invention relates to the use of said article for absorbing blood.

The invention combines organic crosslinking and inorganic crosslinking of super absorbent resin surface modification, and the combination is not simple physical superposition but is an innovative 'organic' combination. The modified solution A and the modified solution B are sprayed on the surface of the super absorbent resin in sequence, the modified solution A is mainly inorganic coordination crosslinking, the crosslinking is relatively loose, and a relatively soft crosslinking layer can be formed, and the modified solution B is an epoxy compound which is easy to chemically crosslink, and the crosslinking can form a relatively hard crosslinking layer with a relatively large crosslinking degree. A. And after the treatment solution B is respectively sprayed, carrying out heat treatment for a certain time together so as to completely carry out two crosslinking reactions. Due to the exquisite design of the feeding process and the post-treatment process, on one hand, the two crosslinking layers have an inside-outside sequence, namely, the compact crosslinking layer is arranged on the core layer, the gel strength of the resin is ensured, and the loose crosslinking layer is arranged on the shell layer, so that the water absorption channel is ensured, and the water absorption rate is also ensured; on the other hand, because of the adoption of a multi-step treatment process, the two-layer distribution presents a gradual change type hierarchical structure instead of a completely isolated two-layer structure due to the diffusion effect, thereby realizing the perfect combination of the water absorption rate and the gel strength, and simultaneously, the formation of the gradual change type hierarchical structure also enables macromolecules such as protein in blood and the like to permeate into the resin through microscopic pores thereof together with water and other small molecules, thereby ensuring the excellent blood absorption performance, having fast absorption speed, and simultaneously having very high gel strength and viscous liquid absorption rate.

Obviously, the process integrates the advantages of the prior art, is simpler and easy to operate, does not need special treatment equipment, and greatly reduces the cost.

Detailed Description

Examples of the present invention are described further below, wherein each example is only an exemplary and/or preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Numerous modifications and variations can be made by those skilled in the art in light of the foregoing description and the following description of the embodiments without departing from the spirit or essential attributes of the invention. Accordingly, the scope of the invention is intended to be limited only by the scope of the claims.

Example 1

(1) Weighing methanol, wherein the mass ratio of the methanol to the sodium polyacrylate resin is 1: 20;

(2) Weighing aluminum sulfate to prepare an aqueous solution A with the mass concentration of 25%; the mass ratio of the aluminum sulfate in the solution A to the sodium polyacrylate resin is 0.025: 1;

(3) Weighing polyethylene glycol diglycidyl ether to prepare an ethanol solution B with the mass concentration of 20%; the mass ratio of the polyethylene glycol diglycidyl ether to the sodium polyacrylate resin in the solution B is 0.0030: 1;

(4) Firstly, uniformly mixing methanol with the solution B, and then uniformly mixing the methanol with the sodium polyacrylate resin at room temperature; then heating the solution A to 60 ℃, and uniformly mixing the solution A with the mixture at 60 ℃;

(5) And (5) putting the resin treated in the step (4) into a tray, and putting the resin into an oven for crosslinking reaction at the reaction temperature of 120 ℃ for 90 minutes to obtain the surface-modified high-absorptivity resin.

Example 2

The same procedure as in example 1 was repeated except that the concentration of solution A in example 1 was changed to 20% and the concentration of solution B in example 1 was changed to 25%.

Example 3

The solution A in the example 1 is changed into an ammonium alum (ammonium aluminum sulfate dodecahydrate) aqueous solution with the mass concentration of 25 percent, and the solution A enters an oven to carry out crosslinking reaction, the reaction temperature is 140 ℃, and the reaction time is 60 minutes, and the method is otherwise the same as the example 1.

Example 4

The solution A in the example 2 is changed into ammonium alum (ammonium aluminum sulfate dodecahydrate) aqueous solution with the mass concentration of 20 percent, and the solution A enters an oven to carry out crosslinking reaction, the reaction temperature is 140 ℃, and the reaction time is 60 minutes, and the method is otherwise the same as the example 2.

Example 5

Changing the solution A in the embodiment 4 into a solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) in water and glycerol, wherein the mass concentration of the solution is 11 percent, the mass ratio of the glycerol to the water is 1: 6, and the solution enters an oven for crosslinking reaction at the reaction temperature of 140 ℃ for 50 minutes; the rest is the same as example 4.

Example 6

The mass ratio of methanol to sodium polyacrylate resin in example 1 was changed to 1: 50, solution B was changed to an ethanol solution with epichlorohydrin mass concentration of 25%, the solvent of solution A was glycerol and water, the mass ratio was 3: 5, and the other examples were the same as example 1.

Example 7

Changing the solution A in the example 6 into a solution of ammonium alum (ammonium aluminum sulfate dodecahydrate) in water and glycerol, wherein the mass concentration of the solution is 11 percent, the mass ratio of the glycerol to the water is 1: 6, and the solution enters an oven for crosslinking reaction at the reaction temperature of 140 ℃ for 50 minutes; the rest is the same as example 6.

Example 8

The same procedure as in example 7 was repeated except that the surfactant in example 7 was changed to ethanol and the mass ratio of ethanol to sodium polyacrylate resin was changed to 3: 100.

Example 9

The methanol, the solution A and the solution B in the embodiment 1 are mixed and then are evenly stirred and mixed with the sodium polyacrylate resin, the solution A is changed into alum water solution, the mass ratio of the methanol to the sodium polyacrylate resin is changed into 1: 10, and other conditions are the same as the embodiment 1.

Example 10

The methanol, the solution B and the solution A in the example 1 are stirred and mixed with the sodium polyacrylate resin uniformly in turn, the solution A is changed into an aqueous solution of aluminum nitrate, and other conditions are the same as the example 1.

Example 11

The methanol, the solution A and the solution B in the embodiment 3 are mixed and then are stirred and mixed with the sodium polyacrylate resin uniformly, the compound containing the epoxy group in the solution B is changed into glycidyl ether, the mass ratio of the glycidyl ether to the sodium polyacrylate resin is 0.0060: 1, and the other conditions are the same as the embodiment 3.

Example 12

The methanol, solution B and solution A in example 3 were mixed with the sodium polyacrylate resin in this order and stirred uniformly under the same conditions as in example 3.

Example 13

The mass ratio of methanol to sodium polyacrylate resin in example 1 was changed to 3: 20, the reaction temperature was changed to 185 ℃, the reaction time was changed to 20 minutes, the solution B was changed to a methanol solution of epichlorohydrin, the mass solubility was 10%, the ratio of propylene oxide to sodium polyacrylate resin was 0.0010: 1, and the other conditions were the same as in example 1.

Example 14

The mass concentration of aluminum sulfate in solution A in example 1 was changed to 10%, the mass ratio of aluminum sulfate to sodium polyacrylate resin was changed to 0.010: 1, and the other conditions were the same as in example 1.

Example 15

The mass concentration of ammonium alum in the solution A in the example 3 was changed to 3%, the mass ratio of ammonium alum to polyacrylic resin was changed to 0.045: 1, and the other conditions were the same as in the example 3.

Example 16

The heating temperature of the solution A in the example 1 was changed to 80 ℃, the heating temperature in the step (5) was changed to 80 ℃, the heating time was changed to 180 minutes, and the other conditions were the same as those in the example 1.

Comparative example 1

The specific process is carried out according to the disclosure in CN 1696181A, and the steps are as follows:

1) Preparing a treatment solution A:

selecting acetone as a dispersing agent, epoxy chloropropane as a cross-linking agent and DMP-30 as a cross-linking promoter; placing a dispersing agent, a cross-linking agent and a cross-linking accelerator in a glass container, and stirring to prepare a treatment liquid A, wherein the mass concentration of the epichlorohydrin is 12%;

2) Preparing a treatment solution B:

putting deionized water into a glass container, heating to 90 ℃, weighing aluminum sulfate salt and a second cross-linking agent glycerol, adding the aluminum sulfate salt and the second cross-linking agent glycerol into the deionized water, and stirring to prepare a treatment liquid B, wherein the mass concentration of aluminum sulfate is 15%;

3) And treating the resin by the treating fluid:

weighing 60kg of sodium polyacrylate resin, placing the sodium polyacrylate resin in a 300-revolution/minute stirrer, spraying the treatment fluid A and the treatment fluid B on the surface of the water-absorbent resin in sequence while stirring, then placing the resin in a tray, heating the resin in an oven to perform crosslinking reaction at the reaction temperature of 120 ℃ for 100 minutes, and finishing the surface modification of the sodium polyacrylate resin.

Hereinafter, the properties/indices of the super absorbent resin of the present invention prepared according to examples 1 to 16 and the sodium polyacrylate resin prepared according to comparative example 1 and the test method thereof will be described in detail.

1. Blood volume, blood rate and gel strength

The test medium was used to test the amount and rate of blood draw of the superabsorbent resin of the invention using human blood and a blood simulant, respectively.

Human blood was purchased from hospitals according to ISO19699-1:2017 The test method described in (E) was used to test the amount and rate of blood absorption (the blood simulant in the test method described in ISO19699-1, 2017 (E) was replaced with human blood for testing), and the specific method was as follows.

Blood simulants according to ISO19699-1:2017 (E) and the test method thereof is in accordance with ISO19699-1:2017 The blood volume and blood rate test methods described in (E) are as follows.

Physical properties of human blood:

through tests, the corresponding parameters of the human blood used by the invention are as follows:

the preparation method of the blood simulation solution comprises the following steps:

a.1 principle

The blood simulation liquid is prepared according to the main physical properties of human blood, has similar flowing and viscosity characteristics, and can well simulate the human blood properties.

A.2 formulation

Unless otherwise indicated, only reagents designated as chemically pure were used in the following reagents. The chemical components of the blood simulant comprise the following substances:

a.3 physical Properties of blood simulants

At (23 ± 1) ° c, the blood simulant will meet the requirements in the following table:

a.4 preparation method

A.4.1 Weighing 10.00g of sodium chloride, 40.00g of sodium carbonate, 1.00g of sodium benzoate and 5.00g of sodium carboxymethylcellulose by using an analytical balance, and sequentially pouring the materials into a 2000mL beaker;

a.4.2 140.00ml of glycerol was measured into a beaker in A.4.1 using a 250ml measuring cylinder, 860g of deionized water was weighed into the beaker in A.4.1 using an analytical balance, and the mixture was stirred uniformly.

A.4.3 Measuring 300ml of the mixed solution in A.4.2 with 500ml measuring cylinder, pouring into a stirrer, turning on the switch and starting timing with a stopwatch, stirring for 7min, turning off the switch, pouring out the mixed solution, and stirring the rest mixed solution.

A.4.4 Stirring the mixed solution obtained after stirring in the step A.4.3 once by using a stirrer according to the method A.4.3, and then adding the mixed solution into the stirred liquid

10.0ml of standard vehicle and 0.05ml of blue pigment are evenly stirred and placed for 24 hours for use.

The method for measuring the absorption amount of the blood simulant comprises the following steps:

b.1 general principles

The amount of the super absorbent resin for absorbing blood in the blood simulant was measured by weighing over a certain period of time.

B.2 reagent

B.2.1 Blood simulation liquid

The blood simulant should be formulated as described above.

B.3 device

B.3.1 Analytical balance: the measuring range is 100g, and the sensing quantity is 0.0001g.

B.3.2 Nylon tea bag: bags of 100mm x 150mm size made from 300 mesh nylon filter cloth with a basis weight of 58g/m ² 。

B.3.3 Glass beaker: the capacity is 2000ml.

B.3.4 A timer: the timing range is 60min, and the accuracy is 0.1s.

B.3.5 The drying rack is provided with a wire clamp and a clamp.

B.3.6 A thermometer: the measuring range is 100 ℃.

B.4 sampling

To ensure that the samples taken from the large bags or containers are representative, the uppermost layer should be removed (about 20 cm). 500 g of the test sample is taken by a spoon and is placed in a proper closed container after 3 min.

Before the samples are tested, they should be placed in a closed container to equilibrate with the ambient temperature of the laboratory. Recommended test conditions are according to ISO291. If the above conditions are not met, the temperature and relative humidity should be recorded.

B.5 measurement procedure

B.5.1 Weighing (1.000 +/-0.005) g of sample to be accurate to 0.0001g, and recording the mass of the sample as m ₀ The samples are poured into the tea (4.8.3.2) and spread on the bottom of the tea bag (the samples attached to the inner side of the tea bag should be poured into the bottom of the tea bag) and are thermally sewn for about 3-5cm along the edge of the opening of the tea bag.

B.5.2 1800mL of the blood simulant (4.8.2.1) was poured into a glass beaker (4.8.3.3), and the tea bags were sequentially placed in the beaker with the blood simulant numbered so that the liquid was immersed and raised 2.0cm above the tea bag while a stopwatch was pressed. (2 groups, i.e. 4 tea bags, at the most, were placed in each beaker).

B.5.3 After 30min, the tea bags are sequentially taken out according to the serial numbers of the tea bags, the upper left corners of the tea bags are folded downwards by about 1/2, and the tea bags are hung on a drying rack by a clamp and hung at an inclined angle of about 45 degrees.

B.5.4 After hanging for 10min, taking down the weighed mass m according to the hanging sequence ₁ When a plurality of samples are tested simultaneously, the samples cannot contact each other.

B.5.5 According to the above method, the blank value of the tea bag used above was measured without placing a sample, and the mass of the blank tea bag after absorbing the liquid was recorded as m ₂

B.6 presentation of the results of the measurement

The blood-simulant absorption amount can be calculated by equation (4):

in the formula:

m-the blood-mimicking fluid uptake of the sample in grams per gram (g/g);

m ₁ -the mass in grams (g) after absorption of liquid by the tea bag containing the sample;

m ₂ -mass in grams (g) of blank test tea bag;

m ₀ -the sample mass weighed in grams (g);

the measurement is carried out twice at the same time, and the arithmetic mean value is taken as the measurement result, and the result is trimmed to one digit after the decimal point.

The method for measuring the absorption rate of the blood simulant comprises the following steps:

c.1 general principles

The rate of absorption of the blood simulant was measured by the liquid-free method in the blood simulant, and the time required for 1g of the sodium polyacrylate resin to absorb 5.0ml of the blood simulant was measured.

C.2 reagent

C.2.1 blood simulants: it should be formulated as described above.

C.3 plant

C.3.1 Analytical balance: the measuring range is 100g, and the precision is 0.0001g.

C.3.2 Glass beaker: the capacity is 100mL.

C.3.3 Glass measuring cylinder, capacity 5.0mL type a or type B (laboratory glassware) (accurate to 0.1 mL).

C.3.4 A timer: the timing range is 60min, and the accuracy is 0.1s.

C.4 sampling

Suitable protective articles such as dust masks or fume hoods should be used to handle samples in excess of 10 g.

To ensure a representative sample is taken from a large bag or container, the uppermost layer should be removed (about 20 cm). 1000g of the test sample is taken by a spoon and placed in a proper closed container after 3 min.

Before the samples are tested, they should be allowed to equilibrate to the ambient laboratory temperature in a closed container. The recommended test conditions are (23. + -.1) ℃ and (50. + -.10)% (ISO 291, class II) relative humidity.

C.5 test procedure

At least two tests were performed according to the following procedure:

c.5.1 Weigh (1.000 + -0.005) g of the sample to be measured on an analytical balance (C.3.1), exactly to 0.001g, and pour into a beaker (C.3.2).

C.5.2 Shaking or tapping the beaker by hand to evenly spread the sample on the bottom of the beaker.

C.5.3 5.0mL of 23. + -. 1 ℃ blood simulant (C.2.1) was measured with a measuring cylinder (C.3.3). Pouring (C.5.2) into the center of the bottom (the pouring is controlled in such a way that the liquid does not splash onto the inner wall of the beaker) and starting the timing.

C.5.4 And when the liquidity of the liquid in the cup disappears, recording the used time t according to a stop second table.

One way to judge complete absorption is to tilt the beaker slightly and observe that there is a flow of liquid.

Representation of C.6 results

The arithmetic mean was calculated from the simulated blood absorption rate measurements and rounded to an integer, expressed in seconds.

The blood simulant absorption rate was calculated from the time taken for 1g of SAP to absorb 5.0ml of blood simulant.

The gel strength was measured according to the method described in the literature reported by Zhu Youliang et al (Zhu Yoghua, uguo, synthesis of water-absorbent resin having core-shell structure, plastics, 2005, 34 (1): 23-26). The test results are shown in Table 1.

TABLE 1 resin Performance test results

As is apparent from the data set forth in Table 1, the superabsorbent resin of the present invention has excellent absorption properties and gel strength regardless of whether the test medium is tested using a blood simulant or actual human blood. Of these, the blood draw was significantly higher and the blood draw rate was much faster than the comparative examples.

2. Residual amount of monomer

The monomer residue (calculated by acrylic acid) of the high-absorptivity resin of the embodiments 1-8 of the invention is less than or equal to 800mg/kg measured according to GB/T20405.2-2006; the residual monomer content (in terms of acrylic acid) of the super absorbent resins of examples 9 to 16 of the present invention was not more than 1000mg/kg.

3. Volatile content

According to the determination of GB/T20405.4-2006, the volatile content of the high-absorptivity resin of the embodiments 1-16 of the invention is less than or equal to 10.0%.

4. pH value

According to the determination of GB/T20405.1-2006, the pH value of the high-absorptivity resin in the embodiment 1-16 of the invention is more than or equal to 5.0 and less than or equal to 8.0.

5. Particle size distribution

The test method is as follows:

5.1 general rule

The quantitative superabsorbent resin is divided into specific particle size fractions by a series of standard sieves. Each component was weighed and reported as a percentage of the total amount.

5.2 apparatus

5.2.1 analytical balance: the measuring range is 1000g, and the precision is 0.01g.

5.2.2 beaker: glass or plastic, capacity 250mL.

5.2.3 vibrating screen: retsch type VE1000 and equivalent. It can be loaded with 3 standard sieves of 200mm diameter with a bottom collection tray and top cover, grounded to prevent static electricity.

5.2.4 Standard Sieve: a stainless steel sieve with a diameter of 200mm, with a pore size of 45 μm,106 μm,150 μm with a bottom collection tray and an upper lid.

5.2.5 brushes: can be prepared from camel hair. For cleaning standard screens.

5.2.6 stopwatch: the measuring range is 60min, and the precision is 0.1s.

5.3 sampling

Warning: suitable protective articles such as dust masks or fume hoods should be used to treat samples in excess of 10 g.

To ensure a representative sample is taken from a large bag or container, the uppermost layer should be removed (about 20 cm). Sampling with spoon, and placing in a suitable sealed container 3min after sampling.

Before the samples are tested, they should be placed in a closed container to equilibrate with the ambient temperature of the laboratory. The recommended test conditions are: (23 +/-2) DEG C and relative humidity (50 +/-10)%. If the above conditions are not met, the temperature and relative temperature should be recorded.

Before taking out the sample from the container for testing, shaking the container for 3-5 times to ensure the sample to be uniform, then standing for 5min, and taking out the sample after uncovering.

5.4 step

5.4.1 ensure the sieve is dry. Each sieve was checked for damage and cleanliness with respect to the light. If the screen is damaged, it should be replaced. The residual particles on the sieve were removed with a brush.

5.4.2 Place the base plate and sieve on a standard shaker in the order of base plate, 45 μm,106 μm,150 μm from bottom to top.

5.4.3 weigh (100+0.01) g of superabsorbent resin sample, noted m _s And put into a beaker.

5.4.4 pour the entire sample in the 5.4.3 beaker into the top screen.

5.4.5 cover the lid and seal according to standard shaker specifications.

5.4.6 ensure that the equipment is grounded against static electricity.

5.4.7 set up the vibrating screen machine according to the following conditions:

-strength: (70. + -.2)% (for Retsch VE1000 type settings).

-the amplitude: 1.0mm.

-the oscillation time: and (5) 10min.

5.4.8 start the vibrating screen machine. After shaking for 10min, the mass of the sample remaining on the 106 μm sieve was weighed and recorded as m ₁ The mass of the sample remaining on the 45 μm sieve was weighed and recorded as m ₂ And the mass of the sample remaining on the base plate is weighed as m ₃ 。

5.5 calculation of

The percentages of each component are calculated according to the following formula:

content of the following samples on a 150 μm sieve: x ₁ ＝[(m ₁ +m ₂ +m ₃ )/m _s ]*100％

Content of the following test specimens on a 106 μm sieve: x ₂ ＝[(m ₂ +m ₃ )/m _s ]*100％

Content of the following samples on a 45 μm sieve: x ₃ ＝[m ₃ /m _s ]*100％

Wherein:

X ₁ the content of the sample below the 150 μm sieve, expressed in%;

m ₁ the mass of the sample remaining on the 106 μm sieve, expressed in g;

m ₂ the mass of the sample remaining on the 45 μm sieve, expressed in g;

m ₃ -the mass of the sample remaining on the chassis, expressed in g;

m _s -total mass of the sample, expressed in g;

X ₂ the content of the sample below the 106 μm sieve, expressed in%;

X ₃ the content of the sample below the 45 μm screen, expressed in%;

and (4) simultaneously carrying out two times of measurement, taking the arithmetic mean value as a measurement result, and trimming the result to the position one after the decimal point.

The particle size distributions of the superabsorbent resins of examples 1-16 of the present invention were determined to be 5% or less (sample content with particle sizes < 150 μm) and 1% or less (sample content with particle sizes < 106 μm).

6. Bulk density

The high-absorbency resins of examples 1-16 of the present invention have a bulk density of 0.65g/cm or more as determined in accordance with ISO17190-9 ³ And is less than or equal to 0.80g/cm ³ 。

7. Whiteness degree

The whiteness of the super absorbent resin of the embodiments 1 to 16 of the invention is more than or equal to 70 percent according to the measurement of GB/T22427.6-2008.

It should be understood that the above examples are only for clarity of illustration and are not intended to limit the embodiments. Other variations and modifications will be apparent to persons skilled in the art in light of the above description. And are neither required nor exhaustive of all embodiments. And obvious variations or modifications therefrom are within the scope of the invention.

Claims

1. A method for preparing high-absorptivity resin is characterized in that: the method comprises the following steps:

(1) Weighing a surface dispersant;

(2) Weighing polyvalent metal salt selected from aluminum salt, calcium salt, magnesium salt or zinc salt to prepare solution A;

(3) Weighing a compound containing an epoxy group to prepare a solution B;

(4) Mixing a surface dispersant, a solution A, a solution B and sodium polyacrylate resin;

(5) Carrying out crosslinking reaction to obtain the surface modified sodium polyacrylate super absorbent resin with a gradual change type hierarchical structure;

in step (4), the surface dispersant and solution B are first mixed uniformly with the sodium polyacrylate resin, and then solution a is mixed uniformly with the previously obtained mixture.

2. The method of claim 1, wherein: the polyvalent metal salt is selected from aluminum salts.

3. The method of claim 1, wherein: the particle size of the sodium polyacrylate resin is 120-830 μm.

4. The method of claim 1, wherein: the particle size of the sodium polyacrylate resin is 150-380 μm.

5. The method of claim 1, wherein: the surface dispersing agent is selected from methanol, ethanol, acetone or gas phase silicon dioxide;

the mass ratio of the surface dispersant to the sodium polyacrylate resin is (1-15): 100.

6. the method of claim 5, wherein: the surface dispersant is selected from methanol or ethanol.

7. The method of claim 5, wherein: the mass ratio of the surface dispersant to the sodium polyacrylate resin is (1-10): 100.

8. the method of claim 5, wherein: the mass ratio of the surface dispersant to the sodium polyacrylate resin is (1-5): 100.

9. The method of claim 1, wherein: the aluminum salt of solution A is selected from aluminum chloride, aluminum sulfate, aluminum ammonium sulfate, aluminum nitrate and alum;

the solvent of solution A is selected from water, acetone and polyhydric alcohol;

the mass concentration of aluminum salt in the solution A is 3-25%;

the mass ratio of the aluminum salt to the sodium polyacrylate resin is (0.010-0.050): 1.

10. The method of claim 9, wherein: the aluminium salt of solution A is selected from aluminium sulphate or aluminium ammonium sulphate.

11. The method of claim 9, wherein: the solvent of the solution A is selected from water and/or glycerol, and the mass ratio of the glycerol to the water is (0-0.7): 1.

12. The method of claim 9, wherein: the mass concentration of the aluminum salt in the solution A is 10-25%.

13. The method of claim 9, wherein: the mass concentration of the aluminum salt in the solution A is 10-20%.

14. The method of claim 9, wherein: the mass ratio of the aluminum salt to the sodium polyacrylate resin is (0.025-0.030): 1.

15. The method of claim 1, wherein: the compound containing epoxy group in solution B is selected from epoxy resin, epichlorohydrin, propylene oxide, glycidyl ether, polyethylene glycol diglycidyl ether and ethylene glycol diglycidyl ether;

the solvent of solution B is selected from alcohols and ketones;

the mass concentration of the compound containing epoxy group in the solution B is 10-25%;

the mass ratio of the compound containing epoxy group to the sodium polyacrylate resin is (0.001-0.006): 1.

16. The method of claim 15, wherein: the compound containing epoxy groups of solution B is selected from epichlorohydrin, glycidyl ether or polyethylene glycol diglycidyl ether.

17. The method of claim 15, wherein: the solvent of the solution B is selected from methanol, ethanol, isopropanol, acetone or butanone.

18. The method of claim 15, wherein: the solvent of the solution B is selected from ethanol or methanol.

19. The method of claim 15, wherein: the mass ratio of the compound containing epoxy group to the sodium polyacrylate resin is (0.002-0.004): 1.

20. The method of claim 15, wherein: the mass ratio of the epoxy group-containing compound to the sodium polyacrylate resin was 0.003.

21. The method of claim 1, wherein: firstly, mixing a surface dispersant with a solution B, and uniformly mixing the surface dispersant with sodium polyacrylate resin at room temperature;

subsequently, solution a is heated to 60-100 ℃ and mixed homogeneously at said temperature with the mixture obtained as described above.

22. The method of claim 21, wherein: solution A was heated to 60-80 ℃.

23. The method of claim 1, wherein: the temperature of the crosslinking reaction in the step (5) is 50-200 ℃; the time is 20-210min.

24. The method of claim 23, wherein: the temperature of the crosslinking reaction in the step (5) is 80-185 ℃.

25. The method of claim 23, wherein: the temperature of the crosslinking reaction in the step (5) is 120-140 ℃.

26. The method of claim 23, wherein: the time of the crosslinking reaction in the step (5) is 25-120min.

27. The method of claim 23, wherein: the time of the crosslinking reaction in the step (5) is 30-90min.

28. The method of claim 1, wherein: when the detection medium is human blood, the absorption capacity of the human blood is more than or equal to 8.0g/g according to ISO 19699-1; the blood absorption rate of the human body is less than or equal to 45s.

29. The method of claim 28, wherein: the absorption capacity of human blood is more than or equal to 8.3g/g.

30. The method of claim 28, wherein: the absorption capacity of human blood is more than or equal to 8.6g/g.

31. The method of claim 28, wherein: the blood absorption rate of the human body is less than or equal to 40s.

32. The method of claim 28, wherein: the absorption rate of human blood is less than or equal to 35s.

33. The method of claim 28, wherein: the blood absorption rate of the human body is less than or equal to 25s.

34. The method of claim 1, wherein: when the detection medium is blood simulant, the absorption capacity of the blood simulant is more than or equal to 18.0g/g according to ISO 19699-1; the absorption rate of the blood simulated fluid is less than or equal to 45s.

35. The method of claim 34, wherein: the absorption capacity of the blood simulant is more than or equal to 18.5g/g.

36. The method of claim 34, wherein: the absorption rate of the blood simulated fluid is less than or equal to 40s.

37. The method of claim 34, wherein: the absorption rate of the blood simulation solution is less than or equal to 38s.

38. The method of claim 28 or 34, wherein: the high-absorption resin: the residual monomer amount is less than or equal to 1000mg/kg based on acrylic acid; the content of volatile matters is less than or equal to 10.0 percent; the pH value is 5.0-8.0; particle size distribution: the content of the sample with the grain diameter less than 150 mu m is less than or equal to 5wt percent, and the content of the sample with the grain diameter less than 106 mu m is less than or equal to 1wt percent; the bulk density is 0.65g/cm3-0.80g/cm3; and/or the whiteness is more than or equal to 70 percent.

39. The method of claim 38, wherein: the high-absorption resin: the residual monomer content is less than or equal to 800mg/kg based on acrylic acid.

40. A superabsorbent resin prepared according to the method of any one of claims 1 to 27, characterized in that: when the detection medium uses the blood simulant, the absorption capacity of the blood simulant is more than or equal to 18.0g/g according to ISO 19699-1; the absorption rate of the blood simulated fluid is less than or equal to 45s.

41. The superabsorbent resin of claim 40, wherein: the absorption capacity of the blood simulant is more than or equal to 18.5g/g.

42. The superabsorbent resin of claim 40, wherein: the absorption rate of the blood simulation solution is less than or equal to 40s.

43. The superabsorbent resin of claim 40, wherein: the absorption rate of the blood simulated fluid is less than or equal to 38s.

44. A superabsorbent resin prepared according to the method of any one of claims 1-27, wherein: when the detection medium is human blood, the absorption capacity of the human blood is more than or equal to 8.0g/g according to ISO 19699-1; the blood absorption rate of the human body is less than or equal to 45s.

45. The superabsorbent resin of claim 44, wherein: the absorption capacity of human blood is more than or equal to 8.3g/g.

46. The superabsorbent resin of claim 44, wherein: the absorption capacity of human blood is more than or equal to 8.6g/g.

47. The superabsorbent resin of claim 44, wherein: the blood absorption rate of the human body is less than or equal to 40s.

48. The superabsorbent resin of claim 44, wherein: the blood absorption rate of the human body is less than or equal to 35s.

49. The superabsorbent resin of claim 44, wherein: the blood absorption rate of the human body is less than or equal to 25s.

50. The superabsorbent resin of claim 44, wherein: when the detection medium is blood simulant, the absorption capacity of the blood simulant is more than or equal to 18.0g/g according to ISO 19699-1; the absorption rate of the blood simulated fluid is less than or equal to 45s.

51. The superabsorbent resin of claim 50, wherein: the absorption capacity of the blood simulant is more than or equal to 18.5g/g.

52. The superabsorbent resin of claim 50, wherein: the absorption rate of the blood simulated fluid is less than or equal to 40s.

53. The superabsorbent resin of claim 50, wherein: the absorption rate of the blood simulation solution is less than or equal to 38s.

54. The superabsorbent resin of any of claims 40 to 53, characterized in that: the high-absorption resin: the residual monomer amount is less than or equal to 1000mg/kg based on acrylic acid; the content of volatile matters is less than or equal to 10.0 percent; the pH value is 5.0-8.0; particle size distribution: the content of the sample with the grain diameter less than 150 mu m is less than or equal to 5wt percent, and the content of the sample with the grain diameter less than 106 mu m is less than or equal to 1wt percent; the bulk density is 0.65g/cm3-0.80g/cm3; and/or the whiteness is more than or equal to 70 percent.

55. The superabsorbent resin of claim 54, wherein: the high-absorption resin: the residual monomer content is less than or equal to 800mg/kg based on acrylic acid.

56. The superabsorbent resin of any one of claims 40 to 53, wherein: the high-absorptivity resin is surface-modified sodium polyacrylate resin.

57. The superabsorbent resin of claim 56, wherein: the surface modification includes surface crosslinking using a solution B formulated from a polyvalent metal salt solution, and from a compound containing an epoxy group and a solvent.

58. The superabsorbent resin of claim 57, wherein: the surface modification uses aluminum salt, calcium salt, magnesium salt and zinc salt solution.

59. The superabsorbent resin of claim 57, wherein: the surface modification uses an aluminum salt solution.

60. A high absorbency article characterized by: the article comprises the high-absorbency resin of any one of claims 40-59, or the sodium polyacrylate high-absorbency resin prepared by the method of any one of claims 1-39.

61. The article of claim 60, wherein: the articles include sanitary napkins and/or medical blood absorbent articles.

62. Use of the article according to claim 60 or 61 for absorbing blood.